<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <button id="connect">连接服务端</button>
  <button id="send" disabled="true">发送数据给服务端</button> <br>
  从服务端接收的数据如下: <br>
  <span id="recv"></span>
  <script>
    var connect = document.querySelector('#connect');
    var send = document.querySelector('#send');
    var recv = document.querySelector('#recv');
    let ws = null
    connect.onclick = function () {
      ws = new WebSocket('ws://localhost:9998')
      // 连接成功事件: ws.onopen
      ws.onopen = function () {
        console.log('连接服务端成功了')
        send.disabled = false
      }
      // 关闭连接事件: ws.onclose
      ws.onclose = function () {
        console.log('连接服务器失败')
        send.disabled = true
      }
      // 接收数据事件: ws.onmessage
      ws.onmessage = function (msg) {
        console.log('接收到从服务端发送过来的数据了')
        console.log(msg)
        recv.innerHTML = msg.data
      }
    }
    send.onclick = function () {
      ws.send(JSON.stringify({
        action: 'themeChange',
        socketType: 'themeChange',
        chartName: 'trend',
        value: 'chalk'
      }))
    }
  </script>
</body>

</html>